Process of making thiocarbonic-acid disulphide



Patented Apr. 2, 1924.

UNITED STATES TPAIT HAROLD s. ADAMS, OF NAUGATUCK, CONNECTICUT, ASSIGNOR TO THE Em OFFICE.

CHEMICAL COMPANY, A CORPORATION OF CONNECTICUT.

PROCESS OFMAKING 'rHIoCAnBomC-ACin DISULPHIDE.

No Drawing.

' making organic disulphides particularly thiocarbonic acid disulphides. "Thein vention includes chlorinating the addition product of carbon disulphide, a caustic alkali and a Inonohydric alcohol.

This application is a continuation in part of my application Serial No. 436,336, filed January 10, 1921.

In its preferred form the process is 'carried out as follows: 25 lbs, of normal butyl alcohol and 28- lbs. of CS are mixed in around bottomed iron kettle provided with a jacket for cooling purposes, and 12% lbs. of powdercd NaOH are gradually added with stirring and cooling. The soda should be added in small amounts and after each addition the mixture should be stirred until the soda is in solution. In case the temperature of the mixture rises to the point where CS boils 01f, the-mixture should be cooled before further amounts of soda are added. During the course of the reaction small quantities of water just suflicient to permit the soda to dissolve, are added. The total quantity of water shouldnot exceed the weight of soda used. Sodium, butyl xanthate tends to separate out if insufficient water is present and it' is generally likely to form at the surface of the mixture. This formation should be continually scraped off and the mixture should be stirred slowly to avoid separation of the xanthate. After all the soda has been added enough water should be added to bring the total quantity up to the weight of soda used.

The reaction mixture is now transferred to atall and narrow lead vessel provided with lead cooling coils and having a draw off cock at its bottom. Chlorine gas is passed into the liquid through a glass tube, reaching to the bottom of the vessel, and as rapidly as possible without letting it, escape absorption. The'amount of chlorine Application file d November 10, 1922. Serial No. 599,960.

needed 'will slightly exceed the amount theoretically necessary to neutralize the soda, specifically 10 to 12 lbs. No stirring is required since the chlorine will sufliciently agitate the liquid. The temperature 9 should be held between 40 and C. by means of the cooling 'coils,"but toward the end of the reaction the temperature should be allowed to rise to complete the reaction and boil off excess of alcohol or CS The reaction is complete when a sample of the supernatant oil formed, will separate definitely as globules and sink to the bottom whenpoured into water, and when the reaction mixture in the vessel has become acid to litmus.

The reason for keeping the temperature low at the beginning of the chlorination is that the product thiocarbonic acid disulphide decomposes rapidly when heated with soda, particularly since the oxy normal butyl thiocarbonic acid disulphide does not separate out as an oil .in the first stages of the reaction. Toward the end of the reaction, when nearly all of the soda has been neutralized, thedanger of decompositionof the disulphide has passed and the.

temperature may .then be allowed to rise, and it-is, in. fact, necessary that it should, in order to complete the reaction as stated.

As soonas chlorination has been com-' pleted, layers of the brine and salt formed should be drawn ofl' from the bottom of the vessel and then the layer of oil consisting of the o'xy normal butyl thiocarbonic acid disul- NAUGATUCK 7 phide should be removed. The latter is now washed thoroughly with water in an earthenware or wooden vessel equipped with a stirrer. The wash water is removed by decantation and the oil is then treated with a hot soda ash solution containing about 5} lbs. per gallon of soda ash dissolved in water and the oil is washed with successive,

portions of the soda ash solution until a sample shows no development of acidity upon boiling with water. The oil is then finally washed again with water and then has a density of approximately 1.17-4.18 at 20 C. It is then dehydrated greferably with calcium chloride and filtere The alcohol, CS and NaOH are present in approximately molecular proportions, an increased amount of SC being added to allow for evaporation. The reactions are rep-' resented by the following equations:

CB|+C4H|0H-)C-=B o-cin, +NaoH-- e=s +1130 The oil obtained by the above process is 0 .normal butylthiocarbonic acid disulphide having the probable formula 'It should be clear and neutral and have a light yellow color. It is miscible with most organic solvents including CS and C,,H,OH.

It dissolves sulphur which can be reprecip-.

. itated on cooling. It reacts in the cold with rious changes may be ammonia and primary amines to form thiourethanes and is decomposed by some metals hence' it should be stored in glass. containers. It becomes viscous at -40 to Q .50 Gland solidifies near -80 to 90 C. It is useful as a rubber vulcanizer.

Although specific proportions and directions have been given in the above preferred embodiment, it is to be understood that vamade without departing from the. scope of the invention. For example, KOH or other caustic alkali may be used either powdered or, in concentrated solution. The method of making the alkali methyl xanthate may be varied by substituting any other method of making alkali methyl xanthates. The lead vessels de scribed above are suitable for use, since they are not attacked by the reaction substances,

K but'other material may be used, such as may , Although the reaction in connection with butyl alcohol, it will be earthenware or any other substance not at-. tacked. N o particular form of apparatus is essential, and such particular apparatus parts as the glass tube above mentioned are not essential but are only mentioned to com-. 'plete the'preferred embodiment. A temperature of 40 to is the preferred range, but the temperature may be varied somewhat from this-range.

has been set forth understood that other alcohols behave similarly. Experiments have been made .with other alcohols which show that the process be carried out in a manner substantially identical with that employed with the .butyl alcohol, it "being only necessary to change the quantity of alcohol employed in the reaction in accordance with its combinof butyl alcohol and CS all in approximately molecular proportions, While keeping the temperature down and adding just enough waterto permit the soda to dissolve, chlorinating the reaction product at about 40 to 50 C. and removing the oil formed.

. 2. i The process of manufacturing oxy normal butyl 'thiocarbonic acid disulphide which comprises adding powdered NaOH to a mixture of butyl alcohol and CS while keeping the temperature down and adding just enough water to permit the soda to dis solve, chlorinating the reaction product at about 40 to 50 C. and purifying the oil formed. c v

3. The process of manufacturing oxy normal butyl thiocarbonic acid disulphide which comprises chlorinating an alkali metal xanthate at about 40 to 50 C. until the alkali has been nearly neutralized and an oil is formed, allowing the temperature to rise 'while completing the, chlorination, and removing the supernatant. oil formed.

4. The process of manufacturing oxy nor-. mal butyl thiocarbonic acid disulphide which comprises making a mixture of 25 lbs. normalbutyl alcohol and 28 lbs. CS adding gradually thereto with stirring and cooling several additions of powderedcaustic soda until a total of 12% lbs. have been added,

adding just sufiicient water with each addition of soda to keep the latter in solution, adding an amount of water sufiicient to bring the total amount up to 12% lbs. after all the soda has been added, chlorinating the reaction product in a lead vessel atlO to 50 C.

until the soda has been'nearly neutralized and an oil forms, then allowing the temperature to rise while completing the chlorination, drawing off the brine and salt formed from the supernatant oil, washing the oil with water until neutral, dehydrating the oil with CaCL, and then filtering it.

/ Signed at Naugatuck, county of New Haven, State'of Connecticut, this 2nd day of A November, 1922.

(HAROLD s. ADAMS. 

